Houston vs San Antonio Air Quality Comparison

Which city has cleaner air right now, from the latest EPA AirNow AQI

As of September 23, 2026, San Antonio, TX has cleaner air than Houston, TX — AQI 55 (Moderate) vs 101 (Unhealthy for Sensitive Groups), a gap of 46 AQI points in the latest EPA AirNow observations. Lower AQI means cleaner air. Houston's reading is driven by O3 and San Antonio's by PM2.5.

Houston, TX

Unhealthy for Sensitive Groups

StateTexas

Dominant PollutantO3

CategoryUnhealthy for Sensitive Groups

View full details →

San Antonio, TX

Moderate

StateTexas

Dominant PollutantPM2.5

CategoryModerate

View full details →

Summary

San Antonio has 46 points better air quality

San Antonio has an AQI of 55 compared to 101

Our Pick

Reduce Indoor Ozone in Houston

Today's main pollutant in Houston is ground-level ozone (AQI 101). Important: standard HEPA filters do NOT remove ozone — only a purifier with a substantial activated-carbon bed adsorbs it. The biggest wins are cutting indoor sources (gas appliances, certain "ionizer" purifiers) and ventilating when outdoor ozone is low (early morning). A high-carbon unit helps with the gases and VOCs that linger indoors.

Best for Gases4.6(8,000+ ratings)

Coway AP-1512HH (HEPA + Carbon)

True HEPA + activated carbon layer · rooms up to 361 sq ft

Heavy activated-carbon bed adsorbs ozone & VOCs that HEPA filters cannot capture

~$230

Check Price on Amazon →

Compare activated-carbon purifiers (for gases & ozone):

Carbon Value

Levoit Core 300

HEPA + Carbon

True HEPA + activated carbon · CADR ~141 CFM · rooms up to 219 sq ft

~$1004.7